To identify the main signaling pathway underlying FOXO3-induced apoptosis in T-ALL cells, we generated CEM/FOXO3 cells overexpressing either anti-apoptotic members of the BCL2 family (BCL2, BclxL), inhibitors of the extrinsic death pathway (caspase-inhibitor CrmA, dominant-negative FADD) or a mutated version of the BH3-only protein BID (dnBID) that cannot be cleaved by caspases [26]. The gene discussed is BCL2L1; the disease is acute lymphoblastic leukemia.